肝内胆管癌（iCCA）以其高度间质纤维化为特征。肿瘤内肌成纤维细胞（iMFs）和肿瘤边缘周围的肌成纤维细胞（pMFs）均存在。我们使用一个以球体为基础的共培养系统，显示最初的iCCA-pMF接触对肿瘤细胞有生长抑制作用。然而，长时间的iCCA-pMF互作会引起明显的肿瘤细胞侵袭和转移。我们发现，血管细胞黏附分子-1（Vcam1）水平在与pMF接触的肿瘤细胞中升高，但在体内和体外的转移性肿瘤细胞中很低。对小鼠和患者的iCCA肿瘤和Vcam1缺失（Vcam1KO）进行基因调控网络分析，表明Vcam1在上皮-间质转化中起重要作用。虽然Vcam1KO对单细胞培养中的肿瘤细胞生长仅有有限影响，但Vcam1KO球体在与pMF共培养时会立即转移并出现严重生长缺陷。当移植到肝脏时，Vcam1KO iCCA细胞表现出类似的转移增加，但建立原发性和转移性肿瘤的能力存在显著缺陷。在体内未完全阻断Vcam1会减小转移灶的大小但增加其数量。总体来说，我们的研究表明，pMFs在Vcam1依赖性的方式下对iCCA的生长和转移进行了时空调节。©2023年作者（们）。

Intrahepatic cholangiocarcinoma (iCCA) is characterized by its highly desmoplastic stroma. Myofibroblasts (MFs) are present both within the tumor mass (intratumoral MFs, iMFs) and at the tumor border (peritumoral MFs, pMFs). Using a spheroid-based coculture system, we show that the initial iCCA-pMF contact is growth suppressive to the tumor cells. However, prolonged iCCA-pMF interaction elicits significant tumor cell invasion and dissemination. We find that vascular cell adhesion molecule-1 (Vcam1) level is elevated in tumor cells in contact with pMFs but low in disseminated tumor cells both in vitro and in vivo. A gene regulatory network analysis of mouse and patient iCCA tumors and Vcam1 knockout (Vcam1KO) demonstrate a heavy involvement of Vcam1 in epithelial-to-mesenchymal transition. While Vcam1KO has only a limited impact on tumor cell growth in their monoculture, Vcam1KO spheroids exhibit instant dissemination and a severe growth defect when cocultured with pMFs. When transplanted into the liver, Vcam1KO iCCA cells show a similar increase in dissemination but a significant defect in establishing primary and metastatic tumors. Incomplete blocking of Vcam1 in vivo reduces the size but increase the number of metastatic lesions. Overall, our study shows a spatiotemporal regulation of iCCA growth and dissemination by pMFs in a Vcam1-dependent manner.© 2023. The Author(s).